Randomized comparison of oesophageal protection with a temperature control device: results of the IMPACT study

Abstract

Aims Thermal injury to the oesophagus is an important cause of life-threatening complication after ablation for atrial fibrillation (AF). Thermal protection of the oesophageal lumen by infusing cold liquid reduces thermal injury to a limited extent. We tested the ability of a more powerful method of oesophageal temperature control to reduce the incidence of thermal injury. Methods and results A single-centre, prospective, double-blinded randomized trial was used to investigate the ability of the ensoETM device to protect the oesophagus from thermal injury. This device was compared in a 1:1 randomization with a control group of standard practice utilizing a single-point temperature probe. In the protected group, the device maintained the luminal temperature at 4°C during radiofrequency (RF) ablation for AF under general anaesthesia. Endoscopic examination was performed at 7 days post-ablation and oesophageal injury was scored. The patient and the endoscopist were blinded to the randomization. We recruited 188 patients, of whom 120 underwent endoscopy. Thermal injury to the mucosa was significantly more common in the control group than in those receiving oesophageal protection (12/60 vs. 2/60; P = 0.008), with a trend toward reduction in gastroparesis (6/60 vs. 2/60, P = 0.27). There was no difference between groups in the duration of RF or in the force applied (P value range= 0.2–0.9). Procedure duration and fluoroscopy duration were similar (P = 0.97, P = 0.91, respectively). Conclusion Thermal protection of the oesophagus significantly reduces ablation-related thermal injury compared with standard care. This method of oesophageal protection is safe and does not compromise the efficacy or efficiency of the ablation procedure.

Finding the heart of the problem: A letter to the editor on ‘Detection of oesophageal course during left atrial ablation’ by Santoro et al.

“…We must add an option that can be used with ICE, if preferred by the operator: Active thermal protection. The IMPACT study [ 4 ] showed that a temperature control device (ensoETM®, Attune Medical, Chicago IL) used to control oesophageal temperature during ablation reduced oesophageal thermal injury by 83.4% compared to control procedures with temperature monitoring. There was no device-related trauma and no reduction in indices of clinical success.…”

Further mechanistic evidence against luminal esophageal temperature monitoring?

“…On the other hand, two pilot RCTs suggest the benefits of active cooling, and a large RCT, the IMPACT study, further confirms this benefit by finding an 83% reduction in esophageal lesion formation using an active cooling device. [6][7][8] With no degradation in ablation efficacy, as well as a reduction/elimination of the need for fluoroscopy and reports of shortened procedure time with active cooling technology, the data of Kar et al, combined with growing clinical data, suggest that continued use of LET monitoring may be unjustified.…”

To the Editor—A double-blind case study?

“…The concept that underpins the method has been verified by mathematical modelling and is supported by a metaanalysis of earlier methods of cooling. 3 Mechanical deviation of the esophagus has the potential to harm, and evidence of esophageal trauma has been demonstrated. 4 Until randomised trial evidence demonstrates protection that outweighs this risk, it makes more sense to use proven alternatives.…”